Algorithm for predicting and mitigating adverse events

ABSTRACT

A patient support apparatus includes a control system operable to gather physiological information about a patient supported on the patient support apparatus. The information may be gathered from sensors, a user interface, or a hospital information system. The control system also monitors operating parameters of the patient support apparatus and environmental conditions in the patient room. The control system utilizes the data gathered to identify a risk of an adverse event occurring to a patient supported on the patient support apparatus. The patient support apparatus is also operable to modify patient support apparatus parameters or environmental conditions to mitigate the risk of the adverse event.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit, under 35 U.S.C. §119(e), ofU.S. Provisional Application No. 61/610,663, which was filed Mar. 14,2012 and which is hereby incorporated by reference herein.

BACKGROUND

The present application is related to a patient support apparatus thatincludes a control system for predicting and mitigating events adverseto the health of a patient supported on the patient support apparatus.More specifically, the present application is directed to a patientsupport apparatus having a control system that gathers informationregarding the patient supported on the apparatus, the environmentalconditions in the room in which the patient support apparatus islocated, and operational characteristics of the patient supportapparatus and acts on that information to predict adverse patient eventsand mitigate those risks.

A patient in a care facility such as a hospital, for example, is oftenin a compromised medical condition and susceptible to developingcomplications. Injury sustained while in a care facility or thedevelopment of complications due to an extended presence in a carefacility result in significant costs to the care facility and thepatient. When these injuries or complications are consideredpreventable, the care facility acquired conditions may not be covered bya patient's insurer or other payers such as Medicare, for example. In aneffort to prevent such injuries and complications, various protocols areimplemented by the management of the care facilities to mitigate therisks. For example, the use of prophylactic antibiotics after surgerymay be a standard institutional practice to mitigate the risk ofsurgical infections. Patients who are at risk of falling when movingunassisted may be identified as fall risks and certain protocols may beimplemented to reduce the opportunity for the patient to move about theroom unassisted.

In response to the desire of healthcare facilities to reduce risks,sensor systems to detect the status of various components of a patientsupport apparatus, such as a bed, for example, have been developed tohelp assure that protocols are being met. For example, patient positionmonitoring systems monitor the movement of a patient on a patientsupport apparatus and alarm if the movement is excessive or a patienthas exited the bed. It is also known to implement alarms for certain bedpositions, such as the amount of elevation of the head section of thebed to assure that a patient is positioned with her upper body at anappropriate angle relative to gravity when various therapies are beingdelivered. Also, the patient support apparatus may include sensors thatdetect when a side rail is in an appropriate position or that the brakesystem of the patient support apparatus is properly engaged. Thisinformation is provided to a central monitoring system, such as a nursecall system, so that deviations from the appropriate conditions may bemonitored by the central system and alarms generated if a protocols arenot being followed.

The use of these bed status variables requires that certain conditionsbe pre-established in the central monitoring system. For example, if thepatient is a fall risk, the central monitoring system must be configuredto monitor for side rail position and bed exit status for the particularpatient support apparatus on which the fall risk patient is positioned.The same is true for other protocol monitoring conditions, the systemmust be configured for a particular patient, and the caregivers mustmodify the alarm conditions based on the particular protocolsimplemented for a given patient. Because of the required activeintervention of the caregivers, protocols are often directed toparticular classes of patients without regard to any patient orenvironmental based mitigating conditions. A change in status of aparticular patient requires the caregiver to implement modifiedprotocols and update any monitoring conditions that may need to bemodified due to the change in the patient's condition.

Several conditions are of significant interest to caregivers based onthe statistical incidence of care facility-based injuries orcomplications. For example, there is strong statistical support for aneed to mitigate the risk of falls in patients who are 65 years orolder. Other patient populations may also be at risk of falls dependingon other medical conditions that are normally assessed at the time ofadmission into a care facility. However, as with any statistic, thereare exceptions that mitigate the risk even in at risk populations. As aresult, applying a “one-size-fits-all” fall prevention program based onage may not provide a patient who has a low risk with the appropriatecare for that particular patient. A patient who has mitigatingconditions which significantly reduce the risk of fall, even thoughtheir age places them in a high-risk group, may be negatively impactedin their recovery if the highest fall prevention protocol is applied tothat particular patient. Generally, a fall prevention program requires apatient to be assisted when ambulating. For a patient who feels healthyand is at low risk of falling, such a protocol may result in the patientbeing noncompliant to other protocols.

Other risks include facility-acquired infections, such as infectionsacquired after a surgery. Patients who are positioned on the patientsupport apparatus for extended periods may also develop pressure ulcerson their skin. Various factors may result in a compromised skincondition that increases the potential of these nosocomial pressureulcers. Another significant risk for bedridden patients is thedevelopment of Ventilator-Associated Pneumonia (VAP). Several factorsmay impact the likelihood of a particular patient acquiring a particularcomplication or suffering a particular injury while in a care facility.

SUMMARY

The present application discloses one or more of the features recited inthe appended claims and/or the following features which alone or in anycombination, may comprise patentable subject matter.

According to a first aspect of the present disclosure, a patient supportapparatus comprises a plurality of sensors, a user interface including aplurality of input devices, a plurality of controllable devices, and acontroller electrically coupled to the plurality of sensors andplurality of controllable devices. The controller includes a processorand a memory device electrically coupled to the processor. The memorydevice includes instructions that, when executed by the processor, causethe processor to process a plurality of data items related tophysiological conditions of a patient associated with the patientsupport apparatus as detected by at least one of the plurality ofsensors or the input devices. The processor analyzes the plurality ofdata items to determine a risk of an adverse event occurring to thepatient.

In some embodiments, the memory device may further include instructionsthat, when executed by the processor, cause the processor identify atleast one data item indicative of an environmental factor associatedwith the environment in which the patient support apparatus is located,analyze the plurality of data items related to the physiologicalconditions of the patient and the data item indicative of anenvironmental factor to determine the risk of an adverse event occurringto the patient.

In some embodiments, the memory device may further include instructionsthat, when executed by the processor, cause the processor to identify atleast one data item indicative of a patient support apparatus factorassociated with the patient support apparatus, analyze the plurality ofdata items related to the physiological conditions of the patient, thedata item indicative of an environmental factor, and the data itemindicative of a patient support apparatus factor to determine the riskof an adverse event occurring to the patient.

In some embodiments, the memory device may include instructions that,when executed by the processor, cause the processor to identify at leastone data item indicative of a patient support apparatus factorassociated with the patient support apparatus, analyze the plurality ofdata items related to the physiological conditions of the patient andthe data item indicative of a patient support apparatus factor todetermine the risk of an adverse event occurring to the patient.

In some embodiments, the memory device may further include instructionsthat, when executed by the processor, cause the processor to output asignal indicative of the risk of an adverse event occurring to thepatient. The signal indicative of the risk of an adverse event occurringto the patient may cause the user interface to display an indication ofthe risk.

In some embodiments, the memory device may include instructions that,when executed by the processor, causes the processor to analyze theplurality of data items related to the physiological conditions of thepatient, the data item indicative of an environmental factor, and thedata item indicative of a patient support apparatus factor to determineif one or more of the data items are associated with a modifiablecondition, and if one or more of the data items are modifiable,determine a value of a first one of the data items which will reduce therisk of an adverse event occurring to the patient.

In some embodiments, the memory device may include instructions that,when executed by the processor, causes the processor to alter the stateof at least one of the controllable devices to alter the value of thefirst data item to the value of the first data item that reduces therisk of an adverse event occurring to the patient.

In some embodiments, the memory device may include instructions that,when executed by the processor, causes the processor determine a valueof a second one of the data items which will reduce the risk of anadverse event occurring to the patient.

In some embodiments, the memory device may include instructions that,when executed by the processor, causes the processor to alter the stateof at least one of the controllable devices to alter the value of thesecond data item to the value of the second data item that reduces therisk of an adverse event occurring to the patient.

In some embodiments, the memory device may further include instructionsthat, when executed by the processor, causes the processor determine avalue for each of the data items which will reduce the risk of anadverse event occurring to the patient.

In some embodiments, the memory device may further include instructionsthat, when executed by the processor, causes the processor to alter thestate of at least one of the controllable devices to alter the value ofeach of the data items to the value of each of the data items thatreduces the risk of an adverse event occurring to the patient.

In some embodiments, the memory device may further include instructionsthat, when executed by the processor, causes the processor to generate aprompt at the display of the user interface indicating to a user thevalue of a first one of the data items necessary to reduce the risk ofan adverse event occurring to the patient.

In some embodiments, the patient support apparatus includes a headsection that is movable to change an attitude of the upper body of apatient supported on the patient support apparatus and at least one ofthe plurality of controllable devices is an actuator for controlling theattitude of the head section of the patient support apparatus.

In some embodiments, the control system analyzes the risk ofventilator-associated pneumonia, and, if the risk of ventilator-assistedpneumonia exceeds a predetermined threshold, the control systemautomatically operates the actuator to increase the attitude of the headsection to exceed a minimum angle.

In some embodiments, the patient support apparatus may include a casterbrake system that is movable between a locked state and an unlockedstate and at least one of the plurality of controllable devices is anactuator for moving the caster brake system between the locked andunlocked states.

In some embodiments, the control system analyzes the risk of a patientfall, and, if the risk of patient fall exceeds a predeterminedthreshold, the control system automatically operates the actuator tomove the caster brake system to a locked state.

In some embodiments, the patient support apparatus includes a sideraillocking system that is movable between a locked state and an unlockedstate and at least one of the plurality of controllable devices is anactuator for moving the siderail locking system between the locked andunlocked states.

In some embodiments, the control system analyzes the risk of a patientfall, and, if the risk of patient fall exceeds a predeterminedthreshold, the control system automatically operates the actuator tomove siderail locking system to the locked state.

In some embodiments, the patient support apparatus includes a siderailactuation system that is operable to move at least one siderail betweena lowered position and a raised position and at least one of theplurality of controllable devices is an actuator for moving the betweenthe lowered and raised positions.

In some embodiments, the control system analyzes the risk of a patientfall, and, if the risk of patient fall exceeds a predeterminedthreshold, the control system automatically operates the actuator tomove siderail to the raised position.

In some embodiments, the at least one of the plurality of controllabledevices is a light controller operable to vary the operation of a lightin the patient room between an illuminated and non-illuminated state.

In some embodiments, the control system analyzes the risk of a patientfall, and, if the risk of patient fall exceeds a predeterminedthreshold, the control system automatically modifies the lightcontroller to illuminate the light.

In some embodiments, the patient support apparatus further comprises asurface including at least one bladder and at least one of the pluralityof controllable devices is a surface pressurization system operable tovary the pressure in the at least one bladder and the control systemanalyzes the risk of a patient developing pressure ulcers, and, if therisk of developing pressure ulcers exceeds a predetermined threshold,the control system automatically modifies the operation of the surfacepressurization system to vary the pressure in the at least one bladderto mitigate the risk of developing pressure ulcers.

According to a second aspect of the present disclosure, a patientsupport apparatus comprises at least one sensor, at least one componenthaving multiple states, at least one actuator operable to vary thestates of the at least one component, and a controller. The controlleris operable to receive an input signal from the at least one sensor, theat least one signal including a first data item indicative of aphysiological condition of a patient supported on the patient supportapparatus and analyze the of data item to determine a risk of an adverseevent occurring to the patient.

In some embodiments, the controller may be operable to determine if therisk of the adverse event exceeds a predetermined threshold.

In some embodiments, if the risk of the adverse event exceeds thepredetermined threshold, the controller operates the at least oneactuator to change the state of the component to reduce the risk of theadverse event.

In some embodiments, the component comprises a caster having a casterbraking mechanism and the controller operates the actuator to move thecaster braking mechanism into a state in which a caster brake isactivated.

In some embodiments, the component comprises a siderail having asiderail locking mechanism and the controller operates the actuator tomove the siderail locking mechanism into a state in which a sideraillock is activated.

In some embodiments, the component comprises a siderail having asiderail moving mechanism and the controller operates the actuator tomove the siderail moving mechanism into a state in which the siderail isin a raised position.

In some embodiments, the component comprises a head section having headsection moving mechanism and the controller operates the actuator tomove the head section moving mechanism into a state in which the headsection is raised beyond a minimum angle. In other embodiments, thecontroller operates the actuator to move the head section movingmechanism into a state in which the head section is raised below amaximum angle.

In some embodiments, the patient support apparatus further comprises auser interface including at least one input device and the controller isoperable to receive a user input signal from the at least one inputdevice, the user input signal including a second data item indicative ofa physiological condition of a patient supported on the patient supportapparatus, and analyze the first data item and second data itemcollectively to determine a risk of an adverse event occurring to thepatient.

In some embodiments, the controller is operable to determine if the riskof the adverse event exceeds a predetermined threshold and if the riskof the adverse event exceeds the predetermined threshold, the controlleroperates the at least one actuator to change the state of the componentto reduce the risk of the adverse event.

In some embodiments, the patient support apparatus includes a pluralityof sensors, at least one of the plurality of sensors providing a signalincluding a second data item indicative of a patient support apparatusfactor, and the controller is operable to analyze the first data itemand second data item collectively to determine a risk of an adverseevent occurring to the patient.

In some embodiments, the controller is operable to determine if the riskof the adverse event exceeds a predetermined threshold and if the riskof the adverse event exceeds the predetermined threshold, the controlleroperates the at least one actuator to change the state of the componentto reduce the risk of the adverse event.

In some embodiments, the patient support apparatus includes a pluralityof sensors, at least one of the plurality of sensors providing a signalincluding a second data item indicative of an environmental factor, andthe controller is operable to analyze the first data item and seconddata item collectively to determine a risk of an adverse event occurringto the patient.

In some embodiments, the controller is operable to determine if the riskof the adverse event exceeds a predetermined threshold and, if the riskof the adverse event exceeds the predetermined threshold the controlleroperates the at least one actuator to change the state of the componentto reduce the risk of the adverse event.

In some embodiments, the component comprises a light control deviceoperable to change the state of a light that illuminates the room inwhich the patient support apparatus is positioned and the controlleroperates the at least one actuator to change the state of the lightcontrol device to turn the light on.

In some embodiments, the patient support apparatus includes a pluralityof sensors, at least one of the plurality of sensors providing a signalincluding a second data item indicative of a second physiologicalcondition of a patient supported on the patient support apparatus, andthe controller is operable to analyze the first data item and seconddata item collectively to determine a risk of an adverse event occurringto the patient.

In some embodiments, the controller is operable to determine if the riskof the adverse event exceeds a predetermined threshold and if the riskof the adverse event exceeds the predetermined threshold, the controlleroperates the at least one actuator to change the state of the componentto reduce the risk of the adverse event.

According to another aspect of the present disclosure, a patient supportapparatus comprises at least one actuator operable to change the stateof a component of the patient support apparatus, at least one inputdevice, and a controller operable to receive a signal from the at leastone input device, process the signal to determine the risk of an adverseevent occurring to a patient supported on the at least one patientsupport apparatus, and if the risk of an adverse event exceeds apredetermined threshold, operate the actuator to change the state of thecomponent to reduce the risk.

In some embodiments, the input device is a sensor that provides a signalrelated to a physiological condition of a patient supported on thepatient support apparatus.

In some embodiments, the actuator activates a caster lock.

In some embodiments, the actuator activates a siderail lock.

In some embodiments, the actuator moves a siderail to a raised position.

In some embodiments, the actuator moves a head section of the patientsupport apparatus to an angle that exceeds a minimum threshold.

In some embodiments, the risk of the adverse event is determined usingpatient physiological data and at least one environmental factorcollectively.

In some embodiments, the risk of the adverse event is determined usingpatient physiological data and at least one patient support apparatusfactor collectively.

Additional features and advantages of the invention will become apparentto those skilled in the art upon consideration of the following detaileddescription of illustrated embodiments exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of the drawings particularly refers to theaccompanying figures in which:

FIG. 1 is a diagrammatic view of a patient support apparatus positionedin a room, with a control system of the patient support apparatus inelectrical communication with other devices, controllers, and systemspositioned inside and outside the room;

FIG. 2 is a diagrammatic representation of the electrical system of thepatient support apparatus of FIG. 1; and

FIG. 3 is a flow chart of an algorithm for predicting and mitigatingadverse events that may occur to a patient supported on the patientsupport apparatus of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

The relationship between a patient support apparatus 14 positioned in aroom 10 of a care facility and a hospital information system 12 is showndiagrammatically in FIG. 1. In the illustrative embodiment, the hospitalinformation system 12 includes a centralized nurse call system 18 and acentralized electronic medical record system 20. Both the nurse callsystem 18 and electronic medical records system 20 include informationthat is related to a patient support apparatus 14 and associated withthe patient stored in memory as related records. The information relatedto the patient stored in memory in the nurse call system 18 andelectronic medical records system 20 is constantly updated asinformation is added to the electronic medical records system 20 and thenurse call system 18 receives information related to the patient and thepatient support apparatus 14.

The patient support apparatus 14 includes a control system 16 that is incommunication with the nurse call system 18. The control system 16includes a user interface 24 that is used by the patient supported onthe patient support apparatus 14 or a caregiver to provide inputs to thecontrol system 16 or display outputs from the control system 16. Asshown diagrammatically in FIG. 1, the electronic medical records system20 is in electrical communication with a user interface 22 positioned inthe room 10 and accessible by caregiver to input patient information andenter orders while the caregiver is in the room 10. The user interface22 may be a personal computer or a dedicated peripheral device. Itshould be understood that other user interfaces may be used throughout afacility to interface with the hospital information system 12, andspecifically the electronic medical records system 20. In theillustrative embodiment of FIG. 1, the user interface 24 is positionedon the patient support apparatus 14 and may be used by caregiver toaccess the electronic medical records system 20 through the controlsystem 16 of the patient support apparatus 14, which is in directcommunication with the electronic medical records system 20 and acts asa peripheral device to the electronic medical records system 20.

The control system 16 is also in communication with an environmentalsystems controller 26 which provides an interface between the patientsupport apparatus 14 and various environmental systems including lights28, heating-ventilating-air-conditioning system 30, and entertainmentdevices 32 such as a television 33 or radio 35, for example. Theenvironmental systems controller 26 provides information to the controlsystem 16 and acts on instructions from the control system 16 to modifyoperation of the environmental systems. Some of the information providedby the environmental systems controller 26 is stored in memoryassociated with the environmental systems controller 26. The informationprovided by the environmental systems controller 26 is updated asoperating parameters of the environmental systems change.

The control system 16 may also be in communication with one or moreperipheral devices 34 positioned in the room 10. The peripheral devices34 each perform a therapy or diagnostic function. For example, theperipheral device 34 may be a ventilator, heart monitor, blood pressuremonitor, infusion device, blood oxygen monitor, sequential compressiondevice, high-frequency chest wall oscillation device, or anotherstandalone diagnostic or therapeutic device. Information used by thecontrol system 16 may be stored in memory associated with a peripheraldevice 34, including the therapy parameters or current operatingconditions of the peripheral device 34. In addition, diagnostic valuessuch as a heart rate, blood pressure, or other diagnostic values may bestored in memory associated with the peripheral device. In some cases,the peripheral devices 34 may communicate to the controller 26 via anetwork connection such as a controller area network (CAN) andinformation stored on a controller of the device 34 may be accessible bythe controller 26. In other cases, the information may be stored by thehospital information system 12. In still other cases, the peripheraldevices 34 may communicate with the controller 26 and the controller 26may store information related to the operator of the peripheraldevice(s) 34 in memory of the controller 26. As illustrated in FIG. 1,any number of peripheral devices 34 may be in communication with thepatient support apparatus 14. It should be understood that peripheraldevices such as the peripheral devices 34, may be in directcommunication with the hospital information system 12 without beingconnected through the patient support apparatus 14.

The nurse call system 18 generates alarms and notifies caregivers ofalarm conditions based on signals from the control system 16 of thepatient support apparatus 14. It is also known in the art for thepatient support apparatus 14 to provide a communication link such asaudio or video communications between a patient supported on the patientsupport apparatus 14 and a nurse positioned at a central nurse callstation 18. It is also known for caregivers to carry communicationbadges that include telephone or other voice communication capability,with the badges providing a direct communication between the caregiverand the central nurse call station 18 or patient, such as the systemdisclosed in U.S. Pat. No. 7,746,218 titled “Configurable System forAlerting Caregivers,” incorporated by reference herein. The nurse callsystem and/or communication badges may facilitate direct communicationbetween a caregiver and a patient positioned on any patient supportapparatus is 14 throughout a care facility. In this way, the nurse callsystem 18 acts as a dispatch system to provide instructions tocaregivers when various conditions warrant the intervention of thecaregiver either to make adjustments to equipment or to respond to theneeds of a particular patient.

The control system 16 of the patient support apparatus 14 includes inputdevices that provide information to a controller 44 of the controlsystem 16. For example, referring to FIG. 2, frame position sensors 36,siderail position sensors 38, support surface sensors 40, a scale system42, and caster brake sensors 46 are all in communication with thecontroller 44. The frame position sensors 36 provide informationregarding the position of various components of the patient supportapparatus 14. Information provided may include the height of the patientsupport apparatus 14, the inclination of a head section, the degree oftilt of an upper frame, or any other frame position data that might beavailable from frame position sensors 36 of the particular patientsupport apparatus 14.

The side rail position sensors 38 provide an indication to thecontroller 44 of whether a particular side rail of the patient supportapparatus is in a raised or lowered position. It is contemplated thatadditional sensors may be implemented which indicate whether aparticular side rail is latched into a particular position. The controlsystem 16 includes siderail actuators 48, siderail locks 50, and casterbrake actuators 52 which are each controlled by the controller 44. Forexample, the patient support apparatus 14 may include motorized siderails such as those disclosed in U.S. Patent Application Publication No.US 2009/0229051, titled “Siderail for a Patient-Support Apparatus,”which is incorporated by reference herein. The patient support apparatus14 may also include locking side rails that include an electromechanicallock, such as those disclosed in U.S. Patent Application Publication No.US 2009/0229051, with the lock retaining the side rail in a particularposition. The siderail actuators 48 are operable to move the siderailsbetween raised and lowered positions. The siderail locks 50 are operableto lock the siderail in a given position. The caster brake actuators 52are operable to activate the caster brake system. For example, thecaster brake actuators may actuate a locking mechanism. For example, thestructures disclosed in U.S. Pat. No. 7,690,059 titled “Hospital Bed” orU.S. Pat. No. 7,200,894 titled “Roller,” each of which is herebyincorporated by reference herein, disclose suitable locking mechanisms.

The support surface sensors 40 provide information regarding theoperation of a support surface 56, such as an inflatable/pneumaticmattress, of the patient support apparatus 14. Such a support surface 56may be integrated into the frame of the patient support apparatus 14 ormay be a separate structure that is operated generally independently ofthe patient support apparatus 14, but communicates with the controller44 of the patient support apparatus 14. The support surface sensors 40may include pressure sensors that identify pressures in particularinflatable structures of the support surface or they may includeposition sensors. For example, accelerometers positioned in particularlocations within the support surface 56 may provide feedback regardingthe amount of inclination of a particular section of the support surface56 relative to gravity, independent of the frame position sensors 36.The support surface sensors 40 may also provide information regardingthe degree of lateral rotation of a patient supported on the supportsurface 56. In addition, the control system 16 includes a supportsurface pressure control system 54 which is operable to control thepressure in one or more air bladders in the support surface 56.

The scale system 42 provides information to the controller 44 regardingthe weight of the patient supported on the patient support apparatus 14.The scale system 42 also provides information regarding the position ofa patient on the patient support apparatus 14 and may provideinformation regarding the degree of movement of the patient. Such asystem is disclosed in U.S. Pat. No. 5,276,432 titled “Patient ExitDetector Mechanism for Hospital Bed” or U.S. Pat. No. 7,437,787 titled“Load-Cell Based Hospital Bed Control,” each of which is incorporatedherein by reference. The data from the scale system 42 may also be usedby the controller to determine if an unexpected weight has been added tothe patient support apparatus 14 or provide other data regardingactivities around the patient support apparatus 14. For example, in anapproach disclosed in U.S. Published Pat. Application No. 2008/0189865titled “System and Method for Controlling an Air Mattress,” which isincorporated herein by reference, the support surface sensors 40 and thescale system 42 cooperate to provide data regarding the position of apatient supported on the patient support apparatus 14. For example, thesupport surface sensors 40 and scale system 42 may cooperate todetermine that a patient is sitting up on a patient support apparatus 14without having the head section raised as disclosed in U.S. PublishedPat. Application No. 2008/0189865.

The caster brake sensors 46 provide information to the controllerregarding the position of the brakes on the patient support apparatus14. For example, casters should be in a locked position to prevent thebed from rolling as a patient attempts to exit the bed. In addition,activation or deactivation of the caster brake sensors 46 may provide anindication of the presence of a caregiver in the room 10 at a particulartime. Activation of other caregiver controls may be considered toidentify the presence of a caregiver in the patient room when thecontrols are activated.

It is within the scope of this disclosure for the patient supportapparatus 14 to include other sensors that provide information to thecontroller 44 regarding the status of portions of the patient supportapparatus 14 and the sensors discussed herein are examples only. Ingeneral, information that is related to the patient is considered to bephysiological information, data items, or factors. This may includediagnostic or therapy information from a peripheral device 34, diagnosesor physical characteristics available from the electronic medicalrecords system 20, including medications being taken or therapies beingreceived, or patient specific information as detected by the scalesystem 42 or support surface sensors 40.

Information related to the patient support apparatus 14 is considered tobe patient support apparatus information, data items, or factors. Theseinclude the positions of members or components of the patient supportapparatus 14, the type of patient support apparatus, the status ofpatient support apparatus functions such as a caster lock or sideraillock.

Information related to the environment as determined and controlled bythe environmental system 26 is considered to be environmentalinformation, data items, or factors. This may include the status ofvarious environmental equipment including room temperature, the statusof lighting, the status of entertainment devices or other similarinformation.

A generalized algorithm for predicting adverse events and mitigating therisk of adverse events is displayed graphically at FIG. 3. The algorithm100 is performed by a processor 58 of the controller 44, utilizinginstructions stored on a memory device 60 of the controller 44. Thealgorithm 100 is performed according to a preset schedule and initiatedby a scheduler of the controller 44 at regular intervals, such as every500 ms, for example. The algorithm 100 may be applied to multiple risksas will be discussed in further detail below. For example, the algorithm100 may be applied to the risk of patient falls, risk of development ofpressure ulcers, the risk of development of ventilator-associatedpneumonia, or other risks that may be discerned from the informationavailable in electronic medical record system, environmental operatingconditions, and patient support apparatus operation variables.

It should be understood that information available to the control system16 may be stored on memory associated with the peripheral devices 34,nurse call system 18, electronic medical records system 20,environmental system 26, or other similar devices or systems. In someembodiments, the control system 16 may receive information from each ofthe sources in real time and update the memory device 60 to include themost recent information available.

At an initial step 102, the controller 44 evaluates the informationnecessary to perform a risk analysis associated with a particular typeof risk. The controller 44 also identifies the availability of thenecessary information from the various sensors 36, 38, 40, 46, scalesystem 42, support surface pressure control system 54, caster brakeactuators 52, siderail actuators 48, siderail locks 50, environmentalsystems 26, peripheral devices 34, and electronic medical records system20 to determine the availability of information used to determine theparticular risk. This information may vary from risk factor to riskfactor, but may also include several common pieces of information aswill be discussed in further detail below. Once the information thatmight be used to determine a particular risk is identified at step 102,at step 104 the controller 44 collects the available information fromvarious data sources including the various sensors 36, 38, 40, 46, scalesystem 42, support surface pressure control system 54, caster brakeactuators 52, siderail actuators 48, siderail locks 50, environmentalsystems 26, peripheral devices 34, and electronic medical records system20.

The algorithm 100 then progresses to decision step 106 where theinformation that was collected from the data sources at step 104 isevaluated to determine if a statistically sufficient amount ofinformation is available to determine the risk of a particular adverseevent. The statistical sufficiency is predetermined from prior analysesof the information. For example, certain key pieces of information mayalways be required, such as the status of the siderails of the patientsupport apparatus 14 may be required for a fall risk analysis, forexample. However, other information may be optional. There may also be aminimum of data items that may be used to perform the analysis. Forexample, in one illustrative embodiment, at least five data values mustbe present to perform the risk analysis. If there is insufficient dataavailable to make a statistically valid evaluation of the risk, thealgorithm 100 proceeds to step 122 where information that is missing maybe available as an input from a caregiver is identified. The algorithm100 then proceeds to step 124 where and indication of the risk status isissued to the system.

Depending on the circumstances, this risk status may be as simple as amessage to the controller 44 that the risk of the particular adverseevent is indeterminable, or the risk status indicator may provideinformation to the controller 44 which causes the controller 44 togenerate an alarm. The response varies depending on the importance ofthe risk. Once the risk status indicator has been set at process step124, the algorithm 100 proceeds to step 126 where the system prompts arequest for information at a user interface 24. The risk is thendisplayed at step 130 and the algorithm 100 monitors inputs at step 128to determine if any new information has been received. If no informationhas been received, the algorithm 100 loops back to step 126 andmaintains the prompt for the request for information from the user atuser interface 24. Thus, until the information necessary to properlyassess the risk is entered, the risk is displayed as an out ofacceptable condition at step 130. If however, new information isreceived at step 128, the algorithm 100 loops back to decision step 106where the new information is evaluated to determine if sufficientinformation is available to make a risk determination.

If insufficient information is determined to be available at step 106,the algorithm 100 loops through again beginning at step 122 andmaintains the display of the risk at step 130.

If sufficient information is available to make the risk determination atstep 106, algorithm 100 proceeds to step 108 and performs a riskassessment. As will be described in further detail below, the riskassessment utilizes the information that is available to determine alevel of risk, or risk score. The risk assessment will return anumerical risk score. The numerical risk score risk is evaluated at adecision step 110. At step 110, the numerical risk score is associatedwith a particular risk level. In some embodiments, if the risk score isgreater than a threshold, the risk is determined to be excessive under abinary analysis. In other embodiments, the risk score may be categorizedinto one of multiple risk indication levels such as low, medium, orhigh. In some cases, the risk will be indicated to a user by a coloredindicator, with green indicating low risk, yellow indicating mediumrisk, and red indicating serious risk, for example. If the risk is notdetermined to be excessive at step 110, the risk status is displayed atstep 130 and the algorithm 100 is suspended until the algorithm 100 isprocessed again by the processor 58.

If the risk is considered to be excessive at step 110, the algorithm 100proceeds to step 112 and issues a risk status indicator updating thedisplay at step 130 and progressing to a step 114. At step 114 ananalysis is performed to determine potential mitigating actions as willbe described in further detail below. Part of the mitigation analysis atstep 114 determines if there are factors that can be modified by thecontroller 44 to mitigate the risk. In addition, other factors that areindependent of the control of the controller 44 that are identified asbeing excessive or out of an acceptable range are placed in an array.The algorithm 100 then proceeds to step 132 and automatically implementsany corrective risk mitigation factors that might be available to thecontroller 44 to reduce the risk to an acceptable level.

The auto correct function at step 132 modifies of operatingcharacteristics of the patient support apparatus 14 as necessary oravailable to mitigate the risks. For example, the controller 44 mayengage the siderail locks 50 to secure a side rail in a raised positionif such action would mitigate a fall risk identified by the algorithm100. As used herein, the term “mitigate” means to reduce the risk score.Other automatically modifiable capabilities include modification ofsupport surface pressure system 54 operating parameters to reduce therisk of development of pressure ulcers, or the modification of theposition of a head section of the patient support apparatus 14 tomitigate the risk of the development of ventilator-associated pneumoniaby raising the head section above a minimum threshold attitude or angle.The caster brakes may be engaged by the caster brake actuator 52.Siderails may be moved to a different position by a siderail actuator48.

It should be understood that the auto correction/modification ofoperating parameters that has been described as occurring at step 132may be optional or may be available for specific operational parametersonly. In some embodiments, a user may program the control system 16 toprevent certain events from occurring automatically, based on userpreferences. Once any available auto correction is completed at step132, the algorithm 100 progresses to step 116 which generates aninstruction to a caregiver to take an action to mitigate the risk. Forexample, the instruction may direct the caregiver to raise a side rail,lock the bed casters, modify the elevation of the patient supportapparatus 14 or some portion of the patient support apparatus 14, orinitialize a therapy, such as continuous lateral rotation therapy, forexample. These are only examples of potential instructions that may begenerated based on the risk identified. In such a case, the instructionsmay identify multiple actions to be undertaken by the caregiver and willidentify the highest priority or largest impact modifications that canbe made to mitigate the risk. The control system 16 provides informationto the caregiver allowing the caregiver to select particular operatingparameters to be modified so as to reduce the risk, at the discretion ofthe caregiver. The caregiver may prefer to implement to lower prioritymodifications to reduce the risk to an acceptable level as opposed toimplementing the highest priority or most heavily weighted factor. Forexample, a particular patient may have a relatively minor fall risk thatcan be mitigated by lowering the bed height and raising a side rail.However, the caregiver may decide that for clinical reasons thepreferred mitigation would be to activate a patient position monitoringfunction of the scale system 42 because the patient is relativelycompliant but prefers to have the side rails down. If such modificationwill lower the risk score to an acceptable level, selectiveimplementation of portions of the instruction may implemented tomitigate the risk.

Once the user has been prompted with instructions for risk mitigation atstep 118, the algorithm 100 monitors the conditions identified in theinstructions to determine if any of those conditions have been modifiedat step 120. If the conditions have been modified, algorithm 100 loopsback to step 108 and re-initializes the risk assessment subroutine todetermine if the modified conditions have reduce the risk to anacceptable level. If no conditions have been modified, the risk statuscontinues to be displayed and the algorithm 100 loops back to step 118and maintains a prompt for user to implement the instructions.

Information used to determine a risk score may include information thatis available form the electronic medical record system 20, theenvironmental systems 26, one or more peripheral devices 34, or any ofthe sensors or systems associated with the patient support apparatus 14.The electronic medical record system 20 includes information that isentered as part of the admissions process and used by all caregivers toassess the mental and physical status of a patient. As this informationhas become more commonly available in electronic form, the ability ofthe controller 44 to access the available information increases theusefulness of the information.

For example, a common analysis used by caregivers is the Morse FallScore which provides a numerical analysis of the risk of fall. The MorseFall Score is based on six factors including the patient's history offalling, any secondary diagnosis related to falls, the type ofintervention the patient requires, whether the patient has an IV orheparin lock, the patient's gait or ability to transfer to furniture,and the patient's mental status. Evaluating these factors usingobjective criteria returns numerical values that are accumulated todetermine the overall Morse Fall Score. The Morse Fall Score is thenused to determine the interventions necessary by caregivers in assuringthat a patient is cared for in a way that mitigates fall risks. It iscontemplated that each of the individual factors in the Morse Fall Scoremay be considered by an adverse event prediction algorithm to assess atleast a portion of the likelihood that a particular patient may fall.

Other factors that may be considered include the extent of any cognitiveimpairment that a patient may suffer. An objective evaluation of thehistory of the patient including having the propensity to fall in thepast may be used as a factor in consideration of a fall risk. Particulartypes of medications that the patient may be taking that affects theircentral nervous system may be assigned a numerical value. For example, apatient taking stimulants, antipsychotics, antidepressants, depressants,anticonvulsants, hallucinogens, or pain medications may indicate a fallrisk. Any mobility impairments the patient may have may also be assessedand assigned a numerical score. For example, a patient who has had ajoint replacement or who is a partial amputee may be assigned a mobilityscore that is less than optimal and may be considered in defining a fallrisk.

The patient's age may also be a factor that is considered with theunderstanding that older patients are likely to suffer some impairedmobility. The patient's gender is also a factor to be considered as itis known that females are a higher fall risk under certain conditions ascompared to males. Evidence of bowel or bladder incontinence may also beconsidered as a factor as this is likely to increase the urgency withwhich the patient may attempt to ambulate. Similarly, a patient whosuffers postural hypotension exhibits an increased risk of falls. Thepatient's height and weight as individual values or the composite valueof body mass index each may be considered in the assessment of thepatient's fall risk under certain circumstances.

While the discussion of fall risk factors should not be consideredcomprehensive, it is clear that a significant amount of information thatis available from a patient's medical record, and therefore theelectronic medical record system, is useful in assessing a patient'srisk of fall. Generally, many if not all of these factors are availablein an electronic medical record maintained on electronic medical recordsystem 20 and available to the controller 44.

In addition to the overall risk factors that are exhibited by a patient,the status of the patient support apparatus 14 on which the patient issupported and any other environmental conditions which are present,provide insight into the potential for the patient fall or provide arisk mitigation to prevent a patient from falling. To the extent thatpatient factors increase the risk of falls, certain bed parameters tendto reduce the potential for falls so that the comparison of those twofactors may arrive at a risk of a particular patient falling at aparticular time.

Some of the factors that may be considered when assessing risk of thepatient fall include the height at which the bed is positioned andwhether the side rails of the patient support apparatus 14 are raised.In addition, the status of a patient position monitoring system or bedexit system may also provide a measure of the likelihood of a patientfalling without intervention by caregiver. Historical data from thepatient position monitor is also useful in assessing the patient's riskof fall in that if the particular patient is causing the patientposition monitoring system to alarm on a regular basis, it is indicativethat the patient is noncompliant with whatever restrictions have beenplaced on the patient by the caregiver. Such an indication may be usedto the discount certain factors, or reduce the weight of certainfactors, if warranted.

Patient support apparatuses 14 that include a scale system may beoperable to detect movement of the patient and establish a patientactivity index that defines a patient fall risk parameter. While patientposition monitoring systems are known to be predictive based onactivities of a patient on the bed, the current position of the patienton the bed considered in conjunction with other risk factors andmitigation factors is a measure of the likelihood of the patient tofall. As discussed above, several approaches to determining the locationof a patient on a patient support apparatus have been disclosed in theart.

Another factor that may be considered in determining the level ofmitigation that has been implemented to reduce the likelihood of thepatient fall includes the status of a bed monitoring system thatprovides an alarm if any of a group of preprogrammed parameters are notin compliance with the monitoring protocol. Yet another factor that maybe considered is whether one or more of the bed operations are in a“locked out” status thereby preventing the patient from activating thefunctions. The status of any caster locking system is another factorwhich may be considered as a mitigation to patient falls.

The particular type of patient support apparatus may be yet anotherfactor as the type of bed may increase the risk of patient falls asdetermined by some statistical analysis. Similarly, the type of patientsupport surface is being used may also provide mitigation factors or bestatistically shown to have a higher incidence of patient falls. Thismay be due to the structure of the patient support surface such ashaving soft edges or other structures which make ingress from thepatient support apparatus more difficult. Still another factor which maybe considered is the state in which the patient support surface isoperating, such as if the patient support surface is in a rotation moderesulting in discontinuities in the top surface of the patient supportsurface or movement of portions of the patient support surface.

The position of various members of the patient support apparatus mayalso be considered in the analysis of the patient's risk of falling. Forexample, if the patient support apparatus is in a chair configuration,the patient is more likely to attempt to egress from the patient supportapparatus. Also, if a knee section or a head section of the patientsupport apparatus 14 is raised during the patient's egress, a patient'slikelihood of falling may be increased due to the uneven surface

Yet another factor to consider is the proximity of a caregiver to thepatient support apparatus 14 as may be detected by the nurse call system18. If the controller 44 identifies that a caregiver is present duringthe attempted egress, some of the factors of fall risk may bediscounted, or the caregivers presence may be considered to be amitigation. Other environmental conditions that may be detected by thecontroller 44 include the status of any room lighting. The controller 44may be able to detect whether an overhead light is on in the room, andnightlight is on the patient support apparatus, indirect lighting beingon in the room, or a reading light on the patient support apparatusbeing on. Similarly, the controller 44 may detect whether a televisionin the patient room is on and the status of the volume of thetelevision. Also, the status of a radio or sound system in the room maybe detected by the controller 44. In some situations, a television thatis on or a radio that is on may lead to distraction to a patient who hasa higher risk of fall such that the television activity or radioactivity should be considered in the risk of fall analysis.

To the extent that the patient support apparatus 14 is in communicationwith any peripheral devices 34, the presence of the peripheral devices34 may be considered in the risk of fall assessment. For example, if thecontroller 44 is aware that a blood oxygen saturation monitor is active,the presence of such a monitoring device may be considered a riskfactor. A similar analysis is applicable to the presence of an infusionpump. Other devices that may be active include heart rate monitors,neurological monitors, ventilators, CPAP devices, drainage devices,would cure devices, sequential compression devices, or the like each ofwhich may be detected by the patient support apparatus 14. In someinstances, data from the peripheral devices 34 may be shared directlywith the controller 44.

While many of the factors considered with regard to falls may also beconsidered with regard to VAP, there are other factors that may beconsidered as well. Pneumonia accounts for approximately 15% of allhospital acquired infections and 25% of all infections acquired incoronary care units and medical intensive care units (ICU) respectively.VAP, a serious subset of these hospital-acquired pneumonia infections,is the most common of all hospital-acquired infections which contributeto death mortality rate of approximately 30%.

VAP increases the patient's stay in the ICU, the overall length ofhospital stay, and adds to overall costs. VAP is a bacterial pneumoniathat develops in patients receiving mechanical ventilator supportthrough an artificial airway. Early-onset pneumonia (those VAP casesthat develop within the first 48 to 72 hours), is usually caused by oneof the following bacteria: staphylococcus aureus (gram positive);haemophilus influenzae (gram negative); or streptococcus pneumoniae(gram positive). These are antibiotic sensitive strains which are commonin the ICU. Late-onset VAP (cases that develop after 72 hours ofventilation) is usually caused by: methicillin resistant staphylococcusaureus (MRSA); pseudomonas aeruginosa; acinetobacter or enterobacter. Inmost patients, VAP is caused by multiple organisms.

VAP rates are reported as cases per 1000 ventilator days. The mean VAPrate for burn patients in the U.S. is 12.3. Neurosurgical patients havethe highest rate at around 20 and pediatrics the lowest at 5.9. Theoverall percentages of hospital-acquired infections in U.S. hospitalsrank urinary as the highest (31%), pneumonia second (27%), and bloodstream third (19%). All three classes of infection are related todevices: urinary catheters, ventilators, and indwelling catheters,respectively.

Grossman reported that with each day of mechanical ventilation andintubation, the crude VAP rate increases by 1% to 3% and the death riskincreases from two-fold to 10-fold (Grossman R F, Fein A. Evidence-BasedAssessment of Diagnostic Tests for Ventilator-Associated Pneumonia:Executive Summary. Chest 2000; 117:177 S-181).

The single largest VAP risk factor is the endotracheal tube. Becausemechanical ventilator support cannot be performed without theendotracheal tube (or other artificial airway), it is a necessarydanger. The endotracheal tube provides a direct passageway into thelungs, bypassing many “natural protection” mechanisms. The endotrachealtube increases the risk for VAP by preventing cough and upper airwayfiltering. VAP also prevents upper airway humidification and inhibitingepiglottic and upper airway reflexes. The VAP acts as a direct conduitinto the lungs for airborne pathogens and potentially acts as areservoir for pathogens by providing a place for biofilm to form. TheVAP inhibits cilliary transport by the epithelium requires a cuff whichprovides a place for secretions to “pool” in the hypoglottic area. TheVAP also initiates a foreign body reaction, thereby interfering with thelocal immune response.

Risk factors that may be considered include a patient age of 65 or more.Also, some underlying chronic illness (e.g. Chronic ObstructivePulmonary Disease (COPD), emphysema, asthma) or diseases causingimmunosuppression increase risks. A patient who is unconscious orsuffers depressed consciousness has a higher risk of VAP. Additionalfactors that increase the risk of VAP include: thoracic or abdominalsurgery; previous antibiotic therapy; and previous pneumonia or remoteinfection.

Other device treatment and personnel related risk factors include:nasogastric tube placement; bolus enteral feeding; gastricover-distension; stress ulcer treatment; a supine patient position;nasal intubation; and nonconformance to hand-washing protocol. Stillother patient factors that may be considered in determining risk includethe patient's perfusion ratio, the patient's SpO₂ measurement, thepresence of acute respiratory distress syndrome, ongoing medicationssuch as sedatives or antibiotics, or the number of previous intubations.The presence of gastric tubes or the use of enteral feedings increasesVAP risk as well. There are standard measures of risk that may also beconsidered including the Predicus™ Risk Score, for example.

To mitigate VAP, it is important that foreign material is not allowed toenter the lungs. This is ensured primarily via regular suction and oralhygiene. The primary patient support apparatus mitigation is to maintainthe head of bed angle (HOB) to 30 degrees or more. Supine body positionis a risk factor for VAP. Elevation of the head of the bed to 30 degreesis strongly supported as a low cost preventive strategy that lowers therisk of aspiration.

Additional mitigations of VAP may be documented in the electronicmedical record system 20 and considered in the risk analysis. Forexample, documentation that care was used to ensure that secretions arenot allowed to spread, such as hand-washing and the use of gowns andgloves may be considered. The completion of suction and oral cleaningprocesses should be documented as well and may be considered in the riskanalysis.

Some of the risk factors that may indicate a fall risk or the risk ofdevelopment of VAP may also be used to determine the risk of a patientdeveloping pressure ulcers, also known as bed sores. Risk factors, inaddition to some of those previously discussed, that may indicate apropensity for the development of pressure ulcers include fecalincontinence, excessive skin moisture, low diastolic blood pressure, ahistory of smoking, and body temperature. Each of these factors may bean indicator of the risk of developing pressure ulcers on the skin.Gender is also a factor with men having a higher propensity for skinbreakdown. A lack of sensory perception limits the patient's ability tofeel the development of a skin injury and may be used by an algorithm toindicate a higher risk of development of pressure ulcers. A lack ofmobility is an additional risk factor. Poor nutrition is still anotherfactor. In some cases, patient mobility may be monitored and excessivetime in a single position may be defined as a risk factor that is thenused to prompt movement of the patient by caregiver or adjustment ofpressure in an inflatable patient support surface. Also, unacceptablelevels of skin moisture or skin temperature, or a combination thereof,may be identified as a risk factor that may be modified by changing theoperation of the patient support surface such as by increasing orreducing a flow of air to the patient interface to increase or decreaseevaporation. Thus, excessively dry or moist skin can be addressed. Also,skin temperature may be modified by cooling the patient interface,cooling air flowing to the patient interface, heating the patientinterface, or heating air flowing to the patient interface.

Non-patient factors may include excessive interface pressure between apatient's skin and a patient support surface. Other factors include thetemperature of the patient support surface and shear or friction betweenthe patient and the support surface. The shear/friction factor may beconsidered as a part of a broader statistical application of risk basedon the type of support surface being used.

The algorithm 100 includes several process steps but relies on theavailability of at least a minimum of information to perform the riskanalysis. Each factor described above is a potential data point in theanalysis and the algorithm 100 is configured to use the available datato perform the analysis, if a minimum amount of data required to performthe analysis with statistical significance is available.

Depending on the algorithm used, each factor has coefficient that isapplied to the factor multiplied by the factor value. Some factors havea value that is normalized to be used in the risk calculation. Otherfactors have a discrete integer value of that is entered depending onthe condition. Still other factors have a binary value of either beingtrue or false.

As a baseline, for example, the risk analysis may require a minimum offive factors be available to perform the risk analysis. The number offactors available may be increased or decreased depending on theparticular risk being analyzed and the statistical significance of thefactors. In one embodiment, the risk is calculated according to thefollowing generalized equation:

$\begin{matrix}{{{{RISK} = {\sum\limits_{1}^{n}\; \frac{C_{x}F_{x}}{n}}};}{n > 4}} & {{Equation}\mspace{14mu} (1)}\end{matrix}$

where: C is the coefficient for a factor x and F is the value for thefactor x. Each coefficient C may be any real number and is selected inan effort to normalize the associated factor F to a relative value thatprovides a risk score related to that factor. Thus, for each of at leastfive factors, because n must be greater than 4, each factor iscalculated to a normalized risk value. Each risk value is thendiscounted by the total number of risk values available forconsideration. If the calculated risk is greater than 1, then a riskcondition exists and should be addressed. It should be understood thatfor factors that have a negative correlation to risk, the coefficientC_(x) is a negative number, thereby reducing the overall score. Whilethe number of factors in the illustrative embodiment is greater thanfour, it should be understood that in some embodiments a fewer number offactors may be considered, so long as sufficient statisticalsignificance can be applied to the analysis.

In another embodiment, the risk score sensitivity may be refined byeliminating the discounting of the normalized score by the number ofsamples and applying a sample-size based coefficient to each factor asshown in Equation 2 below:

RISK=Σ₁ ^(n)C_(x) _(n) F_(x);n>4  Equation (2)

where: C is the coefficient for a factor x when the number of factorsavailable is n and F is the value for the factor x. For factors thathave a negative correlation to risk, the coefficient C_(x) is negativenumber, thereby reducing the overall score. With Equation 2, thecoefficient normalizes the factor to account for the sample size so thatthe factor is properly weighted.

The approach of Equation 2 permits strongly correlative factors to beweighted heavily and factors that correlate less strongly to be weightedat lightly. It should be understood that any of a number of approachesmay be applied to weight the different factors that affect the risk ofan adverse event occurring. Determination of the factors to be used andthe weighting of the factors may vary from application to application.For example, the patient's weight may be considered as a factor in boththe analysis of fall risk and the analysis of the risk of developing bedsores. However, the coefficients of weight are likely to be different ineach risk analysis.

Although the invention has been described with reference to thedisclosed embodiments, variations and modifications exist within thescope and spirit of the invention as described and defined in thefollowing claims.

1. A patient support apparatus comprising a plurality of sensors, a userinterface including a plurality of input devices, a plurality ofcontrollable devices, and a controller electrically coupled to theplurality of sensors and plurality of controllable devices, thecontroller including a processor and a memory device electricallycoupled to the processor, the memory device including instructions that,when executed by the processor, cause the processor to process aplurality of data items related to physiological conditions of a patientassociated with the patient support apparatus as detected by at leastone of the plurality of sensors or the input devices and analyze theplurality of data items to determine a risk of an adverse eventoccurring to the patient.
 2. The patient support apparatus of claim 1,wherein the memory device further includes instructions that, whenexecuted by the processor, cause the processor identify at least onedata item indicative of an environmental factor associated with theenvironment in which the patient support apparatus is located, analyzethe plurality of data items related to the physiological conditions ofthe patient and the data item indicative of an environmental factor todetermine the risk of an adverse event occurring to the patient.
 3. Thepatient support apparatus of claim 2, wherein the memory device furtherincludes instructions that, when executed by the processor, cause theprocessor to identify at least one data item indicative of a patientsupport apparatus factor associated with the patient support apparatusis located, analyze the plurality of data items related to thephysiological conditions of the patient, the data item indicative of anenvironmental factor, and the data item indicative of a patient supportapparatus factor to determine the risk of an adverse event occurring tothe patient.
 4. The patient support apparatus of claim 1, wherein thememory device further includes instructions that, when executed by theprocessor, cause the processor to identify at least one data itemindicative of a patient support apparatus factor associated with thepatient support apparatus, analyze the plurality of data items relatedto the physiological conditions of the patient and the data itemindicative of a patient support apparatus factor to determine the riskof an adverse event occurring to the patient.
 5. The patient supportapparatus of claim 4, wherein the memory device further includesinstructions that, when executed by the processor, cause the processorto output a signal indicative of the risk of an adverse event occurringto the patient.
 6. The patient support apparatus of claim 5, wherein thesignal indicative of the risk of an adverse event occurring to thepatient causes the user interface to display an indication of the risk.7. The patient support apparatus of claim 4, wherein the memory devicefurther includes instructions that, when executed by the processor,causes the processor to analyze the plurality of data items related tothe physiological conditions of the patient, the data item indicative ofan environmental factor, and the data item indicative of a patientsupport apparatus factor to determine if one or more of the data itemsare associated with a modifiable condition, and if one or more of thedata items are modifiable, determine a value of a first one of the dataitems which will reduce the risk of an adverse event occurring to thepatient.
 8. The patient support apparatus of claim 7, wherein the memorydevice further includes instructions that, when executed by theprocessor, causes the processor to alter the state of at least one ofthe controllable devices to alter the value of the first data item tothe value of the first data item that reduces the risk of an adverseevent occurring to the patient.
 9. The patient support apparatus ofclaim 8, wherein the memory device further includes instructions that,when executed by the processor, causes the processor determine a valueof a second one of the data items which will reduce the risk of anadverse event occurring to the patient.
 10. The patient supportapparatus of claim 9, wherein the memory device further includesinstructions that, when executed by the processor, causes the processorto alter the state of at least one of the controllable devices to alterthe value of the second data item to the value of the second data itemthat reduces the risk of an adverse event occurring to the patient. 11.The patient support apparatus of claim 7, wherein the memory devicefurther includes instructions that, when executed by the processor,causes the processor determine a value for each of the data items whichwill reduce the risk of an adverse event occurring to the patient. 12.The patient support apparatus of claim 11, wherein the memory devicefurther includes instructions that, when executed by the processor,causes the processor to alter the state of at least one of thecontrollable devices to alter the value of each of the data items to thevalue of each of the data items that reduces the risk of an adverseevent occurring to the patient.
 13. The patient support apparatus ofclaim 7, wherein the memory device further includes instructions that,when executed by the processor, causes the processor to generate aprompt at the display of the user interface indicating to a user thevalue of a first one of the data items necessary to reduce the risk ofan adverse event occurring to the patient.
 14. The patient supportapparatus of claim 1, wherein the patient support apparatus includes ahead section that is movable to change an attitude of the upper body ofa patient supported on the patient support apparatus and at least one ofthe plurality of controllable devices is an actuator for controlling theattitude of the head section of the patient support apparatus.
 15. Thepatient support apparatus of claim 14, wherein the control systemanalyzes the risk of ventilator-associated pneumonia, and, if the riskof ventilator-assisted pneumonia exceeds a predetermined threshold, thecontrol system automatically operates the actuator to increase theattitude of the head section to exceed a minimum allowable angle. 16.The patient support apparatus of claim 1, wherein the patient supportapparatus includes a caster brake system that is movable between alocked state and an unlocked state and at least one of the plurality ofcontrollable devices is an actuator for moving the caster brake systembetween the locked and unlocked states.
 17. The patient supportapparatus of claim 16, wherein the control system analyzes the risk of apatient fall, and, if the risk of patient fall exceeds a predeterminedthreshold, the control system automatically operates the actuator tomove the caster brake system to a locked state.
 18. The patient supportapparatus of claim 1, wherein the patient support apparatus includes asiderail locking system that is movable between a locked state and anunlocked state and at least one of the plurality of controllable devicesis an actuator for moving the siderail locking system between the lockedand unlocked states.
 19. The patient support apparatus of claim 18,wherein the control system analyzes the risk of a patient fall, and, ifthe risk of patient fall exceeds a predetermined threshold, the controlsystem automatically operates the actuator to move siderail lockingsystem to the locked state.
 20. The patient support apparatus of claim1, wherein the patient support apparatus includes a siderail actuationsystem that is operable to move at least one siderail between a loweredposition and a raised position and at least one of the plurality ofcontrollable devices is an actuator for moving the between the loweredand raised positions.
 21. The patient support apparatus of claim 20,wherein the control system analyzes the risk of a patient fall, and, ifthe risk of patient fall exceeds a predetermined threshold, the controlsystem automatically operates the actuator to move siderail to theraised position.
 22. The patient support apparatus of claim 1, whereinthe at least one of the plurality of controllable devices is a lightcontroller operable to vary the operation of a light in the patient roombetween an illuminated and non-illuminated state.
 23. The patientsupport apparatus of claim 22, wherein the control system analyzes therisk of a patient fall, and, if the risk of patient fall exceeds apredetermined threshold, the control system automatically modifies thelight controller to illuminate the light.
 24. The patient supportapparatus of claim 1, wherein the patient support apparatus furthercomprises a surface including at least one bladder and at least one ofthe plurality of controllable devices is a surface pressurization systemoperable to vary the pressure in the at least one bladder and thecontrol system analyzes the risk of a patient developing pressureulcers, and, if the risk of developing pressure ulcers exceeds apredetermined threshold, the control system automatically modifies theoperation of the surface pressurization system to vary the pressure inthe at least one bladder to mitigate the risk of developing pressureulcers.